I recommend you get a hovobator or LG for $40-50 before you spend over $100 because you want an incubator for just a small amount of eggs. You can put as few eggs in those as you want. If you decide to make an incubator, I would suggest spending the $20 for a wafer thermostat and switch instead of trying the hot water heater thermostat. The range of temps for the hot water thermostat is so large it is hard to regulate. My hatcher has a wafer thermostat and the light turns on at 99.5 and turns off at 101. It has worked wonderfully. If you have used material for the homemade bator you can make it pretty cheap. I used glass from an old picture frame as the viewing window, and styrofoam coolers are pretty cheap. Get a light, wire it all together and there you go.
